Rotary ventilator



Patentefi y 16, 1922. 2 suns-sum 1.

..-..| lllll I l Ll l l ll'l llillll W. F. HIRSCHMAN.

ROTARY VENTILATOR- APPLICATION FILED SEPT- 13. 1920.

w. F. HIRSCHMAN. V

V ROTARY VENTILATOR.

APPLICATIQN FILED SEPT. 13. 1920.

. 1 41 2925 I Patented May16,1922.

2 SHEETSSHEET 2. if

all.

F BUFFALO, NEW YORK. t

ROTARY VENTILATOR.

Specification of Letters Patent.

Patented May 1%, 1922.

To all whom it may concern:

Be it known that I, VVLJLIAM F. Hinsoir- MAN, a citizen of the UnitedStates, esiding in Buffalo, in the county of Erie and State of New York,have invented new and useful Improvements in Rotary Ventilators, ofwhich the following is a specification.

This invention relates to a rotary ventilator whereby the pressure ofthe wind or air currents is utilized to draw out or suck objectionablegases and foul air from the buildings, and to discharge the same intothe outside atmosphere.

One of the objects of the invention is to produce a device of thischaracter which will have the greatest pneumatic-dynamic efficiency forany given wind speed and which will furthermore operate at very low windpressures. A further object of the invention is to produce a rotaryventilator which will prevent any entrance of rain intothe vent pipe,either when rotating or when standing still. A still further object ofthe invention is to prevent any possibility of a back draft down thevent pipe when the velocity of the wind is extremely high.

in the accompanying drawings:

Figure 1 is a side elevation of the improved rotary ventilator. Figure 2is a medial section through the axis thereof. Figure 3 is a top plan ofthe same. Figure 1 is a fragmentary horizontal section looking up andtaken on line 4-4i, Fig. 2. Figure 5 is also a fragmentary horizontalsec tion, but taken on line 55, of Fig. 2.

Similar characters of reference refer to like parts throughout theseveral views.

9 represents the usual vertical cylindrical vent pipe which is adaptedto be connected to any of the piping of a ventilating system (not shown)from which foul air and objectionahle are drawn and dispelled into theoutside air. It is customary to connect this vent pipe to the upper endof a chimney or vertical vent conduit which passes through and projectssome distance above the roof of the building which is to be ventilated.Secured to the outer rim or upper edge of said vent pipe and flaringdownwardly and outwardly therefrom is an annular deflection ring o skirt10 which prevents any rising currents of air from curling up and overthe upper edge of the vent pipe and thereby tending to cause a backdraft down the vent pipe or at least iInpeding the proper flow of foulair from said pipe. Arranged within said vent pipe 9 and secured to theinner face thereof are a number of vertical web plates 11, whose innerends are mutually connected together and collectively act as a supportfor a vertical hollow tube or hearing sleeve 12. This sleeve as well asthe web plates 11 and also the vent pipe 9, are stationary at all times.Secured coaxially to the uppe and lower ends respectively of saidbearing sleeve 12 are a pair of cup-shaped bearing casings 13 and 1%arranged to receive suitable ball bearings and races whichanti-frictionally support a vertical rotatable shaft 15. The upper ballbearings which are received by the upper casing 13 carry. of course,only a radial load, whereas the ball. hearings in the lower casing 1 1carry both a radial as well as a longitudinal, vertical loading.

Secured to the said vertical otatable shaft 15 and disposed coaxiallywith respect to the vent pipe 9, is a conical upwardly tapering rotarydome 16. The diameter of this dome is considerably greate than thediameter of the said vent pipe, and from its peripheral edge depends anannular, vertical flange or apron 17 whose lower edge extends somedistance below the uppe edge of the vertical vent pipe 9. Secured t0 thelower inclined face of the rotary dome and arranged in a circumferentialrow are a considerable number of suction blades 18 each of which isinclined somewhat or arranged obliquely relatively to a perpendiculaplane passing through the axis and through said suction blade so as toact in the manner of'an ordinary propeller blade. Each of these suctionblades 18 is secured at its lower end to an annula stiffening ring 20which is dis posed just above and adjacent to the aforementioned skirt1() of the vent pipe 9, the adjacent faces of said skirt and saidstiffening ring being substantially parallel to each other.

Connected integrally'to the inner ends of a relatively small number ofthe suction blades 18, are a number of centrifugal blades which aredisposed perpendicularly, lying in planes which pass through the axis ofrotation of the rotary dome. It will be noticed that the'suction blades18 do not lie above the opening or hole of the vent pipe 10, but aredisposed outwardly of the periphery thereof. These vertical, centrifugalblades 21, however extend radially inwardly over the rim of said ventpipe 9 and.

project beyond the periphery thereof and are disposed above the centralopening of said vent pipe. The space above the upper edge of the ventpipe 9 and below the lower face of the dome 16 may be denominated acentrifugal chamber 25 inasmuch as the action of the air currentstherein is analogous to the action in the centrifugal chamber of anordinary centrifugal pump. It is very important however that the airwhich passes upwardly from the vent pipe into said centrifugal chamber25 and thence downwardly past the suction blades 18, should not beimpeded. It is for this reason that the centrifugal blades are muchfewer in number than the suctions blades, it being permissible ofcourse, to employ a quite large number of suction blades, inasmuch asthe same are disposed a considerable distance outwardly of the axis ofrotation of the rotary dome. Any interference of the particularaircurrents, which pass close to the axis of the dome, is furthermoreminimized by cutting off each of the centrifugal blades 21 on a linewhich extends from the inner edge of the stiffening ring 20 up towardthe apex of the dome. centrifugal blades only extend radially inwardly asuillicient distance to ensure that the air be caught up from the saidcentrifugal chamber 25 and ejected therefrom without, however, cloggingup said centrifugal chamber or interfering with the free and efficientflow of air therethrough.

The rotation of the dome is accomplished by securing a number ofpropeller buckets or blades 26 to the upper inrlined face of theconical, rotary dome 16. For one half of the rotation of the dome thesepropeller blades are travelling of course, with the wind, and theremaining half rotation against the wind. The construction of the blade.when travelling with the wind involves obviously no difficulties.Therefore, we will deal with the blades when travelling against thewind, i. e., to the left as shown in Fig. 1. Each of these propeller bladcs has its forward or leading edge 27 disposed substantially flushwith the upper surface of the dome, while the main body of each bladeextends rearwardly and upwardly from said leading edge and terminates ina trailing edge 28. The intermediate or central portion 30 of theleading edge of each propeller blade is pointed, i. e., it extends somedistance forwardly of the rest of the leading er go 27. [By thisconstruction the relatively static body of air which lies adjacent thefront or outer face of each propeller blade when the blade is travellingagainst the wind is separated or opened up gradually, such an actionbeing in accordance with accepted pneumatie-dynamic practice. Theintermediate portion 31 of the trailing edge 28 of each propeller bladeoverhangs or ex- In thisv way, the said tends considerably furtherrearwardly than the rest of the said trailing edge. This prevents anundue vacuum from forming under the propeller blade when the same istravelling against the wind, as otherwise the rotation of the wholerotary dome would be retarded. This action results from the fact that(as the air starts to flow back over the trailing edge 28 when the bladeis moving in the half revolution against the wind) the said air currentsfirst curl over the outer ends of the trailing edge 28, during the timethat a partial vacuum is still being formed behind the overhang 31 ofthe trailing edge. This causes a lateral flow of air toward the underpart of the overhang. 31, thus effectively killing the vacuum under theentire rear faces of the propeller blades by reason of the lateral aircurrents so induced. On the other hand, when the propeller blade istravelling with the wind, this overhanging portion 31 cuts the aircurrent and curls the same under the concave or propelling face of thepropeller blade similarly to the manner in which the leading edge of anaeroplane wing deflects the air downwardly against the main body of theaeroplane wing.

In the operation,the entire dome is rotated by a number of propellerblades 26 whose leading edges 27 are pointed at 30 so as to enter thedead air easily while the central parts of the trailing edges 28overhang at 31 so as to kill the vacuum under said'blades when saidblades are travelling against the wind. The'foul air from the buildingwhich is to be ventilated, rises up the vent pipe 9 into the centrifugalchamber 25. Here it is caught up by a small number of centrifugal blades21 which however do not project sufficiently into said centrifugalchamber as to impede the flow of air therethrough. Thence the air isdeflected downwardly by a large number of suction blades 18 which propelthe air in a manner similarly to an ordinary propeller blade, i. e., theblades being inclined to the path of the air flow. These suction bladesare arranged entirely outside of the centrifugal compartment so as notto interfere with the flow of air therethrough, the circumferential areaof air path being of course much greater where the air travels throughthe suction blades than it is near the center in the centrifugal chamber25. The suction blades 18 are located a considerable distance above thelower edge of the annular apron 17 and the space intermediate of saidapron and said vent pipe is thereby filled with compressed air which ismoving downwardly. Thus any tendency of the outside wind to curl upbehind the apron on the particular side which happens, at the time, tobe lying toward the oncoming wind, is frustrated, because this windwould have to first rise a considerable distance before coming incontact with the suction blades. Before such an action can occur thedome 16 has had time to turn around sufficiently so that the pressure ofthe external rising air is lowered on the leeward side of the ventilatorand the pressure of the downcoming air from the suction blades renderedsufficient to overcome this rising current. Upward currents of externalair are also discouraged by means of the skirt 10 on the upper outeredge of the vent pipe. Thus the ventilator will operate properly eventhough its lubricating system be neglected so that it turnscomparatively slowly. The ventilator will turn, however, in very lightbreezes, and at no time can any rain come into the vent pipe inasmuch asthe same is completely covered.

I claim as my invention:

1. A rotary ventilator comprising a rotatable dome, and a propellerblade secured to said dome and having a pointed leading edge and atrailing edge which overhangs the outer surface of said dome, theintermediate portion thereof extending rearwardly more than the otherparts of said trailing edge and said intermediate portion being locatedat a point substantially in circumferential alignment with said leadingedge.

2. A rotary ventilator comprising a rotatable dome, and a propellerblade secured to said dome and having a pointed leading edge which islocated intermediate of the axis and the periphery of said rotatabledome and which terminates flush with the surface of said rotatable dome,said propeller blade having a trailing edge which is disposed outwardlyof the surface of said rotatable dome and overhangs rearwardly a lineextending from the outer to the inner end of the blade at a pointcircumferentially in alignment with said leading edge.

3. r rotary ventilator comprising a conical rotatable dome, and apropeller blade whose leading edge is flush with the outer surface ofsaid conical dome and extends forwardly at a point intermediate of theaxis and the periphery of said dome, the main portion of said propellerblade extending rearwardly and outwardly away from said leading edge andterminating in a trailing edge which overhangs rearwa-rdly a lineextending from the outer to the inner end of the blade at a pointintermediate of the axis and the periphery of the dome, substantially asdescribed.

4. A rotary ventilator comprising a vent pipe, a rotatable dome arrangedabove and covering the upper end of said vent pipe, a centrifugal bladedisposed radially with respect to the axis of the rotatable dome andextending from the peripheral part of said dome inwardly over the upperend of said vent pipe.

5. A rotary ventilator comprising a vent pipe, a conical rotatable domehaving a depending peripheral apron and mounted sufficiently above theupper end of said vent pipe so as to form a centrifugal chamber, and avertically disposed flat centrifugal blade secured to the lower face ofsaid dome and extending radially into said centrifugal chamber and overthe edge of said vent pipe.

6. A. rotary ventilator comprising a vent pipe, a conical upwardlytapering dome mounted coaxially with respect to said vent pipe, acentrifugal blade secured to and extending vertically downwardlytherefrom and having an inner edge which extends from approximately theupper rim of the vent pipe obliquely upwardly and inwardly toward theapex of said dome.

7. A rotary ventilator comprising a vent pipe, a conical upwardlytapering rotatable dome provided with an annular downwardly hangingapron which extends below the top of said vent pipe, and a plurality ofsuction blades secured to the lower face of said dome and disposedinwardly of said apron and outwardly of said vent pipe.

8. A rotary ventilator comprising a vent pipe, a rotatable dome arrangedabove the upper end of said vent pipe, a circumferential row of suctionblades secured to the lower face of said dome and disposed outwardly ofsaid vent pipe, and centrifugal blades extending inwardly over the rimof said vent pipe, said centrifugal blades being comparatively few innumber while said suction blades are very numerous.

9. A rotary ventilator comprising a vertical vent pipe, a rotatable,conical dome mounted coaxially therewith and provided with a verticalperipheral apron extending below the upper end of said vent pipe, and aconical skirt secured to the rim of said vent pipe and projectingdownwardly and outwardly therefrom.

10. A rotary ventilator comprising a vertical vent pipe, a rotatableconical dome extending below the upper end of said vent pipe and largerin diameter than said vent pipe, and a plurality of suction bladessecured to said dome and reversing the direction of flow of the air fromsaid vent pipe, causing said air to be forced vertically downwardlythrough the space intermediate of the outer face of the vent pipe andthe inner face of the dome.

11. A rotary ventilator comprising a vent pipe, a rotatable dome, astiffening ring arranged coaxially with respect to said dome, aplurality of suction blades and a number of centrifugal blades securedat opposite ends respectively to said stiffening ring and to said dome.

12. In a rotary ventilator, the combination of a vent pipe, a domerotatably mounted on said vent pipe, a plurality of suction bladessecured to said dome and disposed outwardly of said vent pipe, andcentrifugal blades also secured to said dome but projecting inwardlyover the rim of said vent pipe.

13. A rotary ventilator comprising a vent pipe, a rotatable dome mountedon said vent pipe and provided with an annular apron which depends fromthe periphery of said dome and which extends below the top of the ventpipe, and a plurality of suction blades secured to said dome above thelower end of said apron, the air from said vent pipe be ing dischargedvertically downwardly from said suction blades and into the space belowwhich lies intermediate of the outer face of the vent pipe and the innerface of the. said 15 dome mounted coaxially with respect to said '20vent pipe, a plurality of suction blades secured to the lower face ofsaid dome, and a stiffening ring secured to the lower ends of saidblades and disposed adjacent to said skirt of said vent pipe.

WILLIAM F. HIRSCHMAN.

